RE: [RFC PATCH 1/5] signal: Teach sigsuspend to use set_user_sigmask

[David Laight]

From: Oleg Nesterov [mailto:oleg@xxxxxxxxxx]
> Sent: 11 June 2019 19:56
> On 06/10, Eric W. Biederman wrote:
> >
> > Personally I don't think anyone sane would intentionally depend on this
> > and I don't think there is a sufficiently reliable way to depend on this
> > by accident that people would actually be depending on it.
> 
> Agreed.
> 
> As I said I like these changes and I see nothing wrong. To me they fix the
> current behaviour, or at least make it more consistent.
> 
> But perhaps this should be documented in the changelog? To make it clear
> that this change was intentional.

What happens if you run the test program I posted yesterday after the changes?

It looks like pselect() and epoll_pwait() operated completely differently.
pselect() would always calls the signal handlers.
epoll_pwait() only calls them when EINTR is returned.
So changing epoll_pwait() and pselect() to work the same way
is bound to break some applications.

	David

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